def testArrayConstructor(self):
"""Test that construction with coefficient arrays yields an object with
copies of those arrays, and that all dimensions must be the same.
"""
order = 3
xc = makeRandomCoefficientMatrix(order + 1)
yc = makeRandomCoefficientMatrix(order + 1)
p = PolynomialTransform(xc, yc)
self.assertEqual(p.getOrder(), order)
self.assertFloatsAlmostEqual(p.getXCoeffs(), xc, atol=0, rtol=0)
self.assertFloatsAlmostEqual(p.getYCoeffs(), yc, atol=0, rtol=0)
# Test that the coefficients are not a view.
old = xc[0, 0]
xc[0, 0] += 100.0
self.assertEqual(p.getXCoeffs()[0, 0], old)
# Test that rectangular coefficient arrays are not allowed.
self.assertRaises(
lsst.pex.exceptions.LengthError,
PolynomialTransform,
np.zeros((5, 4), dtype=float),
np.zeros((5, 4), dtype=float)
)
# Test that x and y coefficient arrays must have the same shape.
self.assertRaises(
lsst.pex.exceptions.LengthError,
PolynomialTransform,
np.zeros((5, 5), dtype=float),
np.zeros((4, 4), dtype=float)
)
def makeRandomPolynomialTransform(order, sip=False):
xc = makeRandomCoefficientMatrix(order + 1)
yc = makeRandomCoefficientMatrix(order + 1)
if sip:
xc[0, 0] = 0
yc[0, 0] = 0
xc[0, 1] = 0
yc[0, 1] = 0
xc[1, 0] = 0
yc[1, 0] = 0
return PolynomialTransform(xc, yc)
def testArrayConstructor(self):
"""Test that construction with coefficient arrays yields an object with
copies of those arrays, and that all dimensions must be the same.
"""
order = 3
xc = makeRandomCoefficientMatrix(order + 1)
yc = makeRandomCoefficientMatrix(order + 1)
p = PolynomialTransform(xc, yc)
self.assertEqual(p.getOrder(), order)
self.assertFloatsAlmostEqual(p.getXCoeffs(), xc, atol=0, rtol=0)
self.assertFloatsAlmostEqual(p.getYCoeffs(), yc, atol=0, rtol=0)
# Test that the coefficients are not a view.
old = xc[0, 0]
xc[0, 0] += 100.0
self.assertEqual(p.getXCoeffs()[0, 0], old)
# Test that rectangular coefficient arrays are not allowed.
self.assertRaises(
lsst.pex.exceptions.LengthError,
PolynomialTransform,
np.zeros((5, 4), dtype=float),
np.zeros((5, 4), dtype=float)
)
# Test that x and y coefficient arrays must have the same shape.
self.assertRaises(
lsst.pex.exceptions.LengthError,
PolynomialTransform,
np.zeros((5, 5), dtype=float),
np.zeros((4, 4), dtype=float)
)
def testConvertSipReverse(self):
"""Test that we can convert a SipForwardTransform to a PolynomialTransform.
"""
sipReverse = makeRandomSipReverseTransform(4)
converted = PolynomialTransform.convert(sipReverse)
self.assertTransformsAlmostEqual(sipReverse, converted)
def testConvertScaledPolynomial(self):
"""Test that we can convert a ScaledPolynomialTransform to a PolynomialTransform.
"""
scaled = makeRandomScaledPolynomialTransform(4)
converted = PolynomialTransform.convert(scaled)
self.assertTransformsAlmostEqual(scaled, converted)
def testMakeWcs(self):
"""Test SipForwardTransform, SipReverseTransform and makeWcs
"""
filename = os.path.join(os.path.dirname(__file__),
'imgCharSources-v85501867-R01-S00.sipheader')
sipMetadata = readMetadata(filename)
# We're building an ICRS-based TAN-SIP using coefficients read from metadata
# so ignore the RADESYS in metadata (which is missing anyway, falling back to FK5)
sipMetadata.set("RADESYS", "ICRS")
crpix = lsst.afw.geom.Point2D(
sipMetadata.get("CRPIX1") - 1,
sipMetadata.get("CRPIX2") - 1,
)
crval = lsst.afw.geom.SpherePoint(
sipMetadata.get("CRVAL1"),
sipMetadata.get("CRVAL2"),
lsst.afw.geom.degrees,
)
cdLinearTransform = lsst.afw.geom.LinearTransform(
getCdMatrixFromMetadata(sipMetadata))
aArr = getSipMatrixFromMetadata(sipMetadata, "A")
bArr = getSipMatrixFromMetadata(sipMetadata, "B")
apArr = getSipMatrixFromMetadata(sipMetadata, "AP")
bpArr = getSipMatrixFromMetadata(sipMetadata, "BP")
abPoly = PolynomialTransform(aArr, bArr)
abRevPoly = PolynomialTransform(apArr, bpArr)
fwd = SipForwardTransform(crpix, cdLinearTransform, abPoly)
rev = SipReverseTransform(crpix, cdLinearTransform, abRevPoly)
wcsFromMakeWcs = lsst.meas.astrom.makeWcs(fwd, rev, crval)
wcsFromMetadata = lsst.afw.geom.makeSkyWcs(sipMetadata, strip=False)
# Check SipForwardTransform against a local implementation
localPixelToIwc = makeSipPixelToIwc(sipMetadata)
self.assertTransformsAlmostEqual(fwd,
localPixelToIwc.applyForward,
maxval=2000)
# Compare SipReverseTransform against a local implementation
# Use the forward direction first to get sensible inputs
localIwcToPixel = makeSipIwcToPixel(sipMetadata)
def fwdThenRev(p):
return rev(fwd(p))
def fwdThenLocalRev(p):
return localIwcToPixel.applyForward(fwd(p))
self.assertTransformsAlmostEqual(fwdThenRev,
fwdThenLocalRev,
maxval=2000)
# Check that SipReverseTransform is the inverse of SipForwardTransform;
# this is not perfect because the coefficients don't define a perfect inverse
def nullTransform(p):
return p
self.assertTransformsAlmostEqual(fwdThenRev,
nullTransform,
maxval=2000,
atol=1e-3)
# Check SipForwardTransform against the one contained in wcsFromMakeWcs
# (Don't bother with the other direction because the WCS transform is iterative,
# so it doesn't tell us anything useful about SipReverseTransform
pixelToIwc = lsst.afw.geom.getPixelToIntermediateWorldCoords(
wcsFromMetadata)
self.assertTransformsAlmostEqual(fwd,
pixelToIwc.applyForward,
maxval=2000)
# Check a WCS constructed from SipForwardTransform, SipReverseTransform
# against one constructed directly from the metadata
bbox = lsst.afw.geom.Box2D(lsst.afw.geom.Point2D(0, 0),
lsst.afw.geom.Extent2D(2000, 2000))
self.assertWcsAlmostEqualOverBBox(wcsFromMakeWcs, wcsFromMetadata,
bbox)
def testConvertSipReverse(self):
"""Test that we can convert a SipForwardTransform to a PolynomialTransform.
"""
sipReverse = makeRandomSipReverseTransform(4)
converted = PolynomialTransform.convert(sipReverse)
self.assertTransformsAlmostEqual(sipReverse, converted)
def testConvertScaledPolynomial(self):
"""Test that we can convert a ScaledPolynomialTransform to a PolynomialTransform.
"""
scaled = makeRandomScaledPolynomialTransform(4)
converted = PolynomialTransform.convert(scaled)
self.assertTransformsAlmostEqual(scaled, converted)